


Killer Cop Instincts

by ACatWhoWrites, topkyungsoo



Category: EXO (Band)
Genre: Alternate Universe, Blood, Blood and Injury, Crime Fighting, Crimes & Criminals, Detectives, Established Relationship, M/M, Murder Mystery, Police, Rated for blood, rated for language
Language: English
Status: Completed
Published: 2021-03-08
Updated: 2021-03-08
Packaged: 2021-03-18 10:20:07
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,907
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/28990593
Author URL: https://archiveofourown.org/users/ACatWhoWrites/pseuds/ACatWhoWrites, https://archiveofourown.org/users/topkyungsoo/pseuds/topkyungsoo
Summary: Detective Do Kyungsoo's worries are twofold: How to tell his boss that he's dating her son and finding a serial murderer before they kill again.[ For top!soo fest round 4: Detective AU ]
Relationships: Do Kyungsoo | D.O/Oh Sehun
Comments: 8
Kudos: 27
Collections: top!soo fest: round 4 (2020-2021)





	Killer Cop Instincts

It's the end of another long, tiring day. Sehun is ready to go home, play some video games, drink booze, and go to bed. He leaves his desk, walking unsteadily on his legs until they stretch a bit, and waves to some coworkers putting in overtime.

Detectives have their own offices. The Byun-Do office is at the center of the floor, on the side opposite Sehun's desk.

He's pretty sure his mother arranged it that way, to lessen distractions. Baekhyun made it obvious he liked the rookie the moment he joined, and although he means well, sometimes he gets tripped up by his own good intentions.

The office door is open, and he hears music softly playing rock 'n roll as well as the shuffle of papers. Baekhyun must be out; it'd never be so peaceful, otherwise.

Kyungsoo sits at his orderly desk, poring over a file as his head bobs to the song. The upbeat tunes don't at all fit the gruesome business of murder, but he's found that he has to take energy and cheerfulness where he can find it, or his soul will sink into the farthest pits of his being.

His current case has him frustrated. There's an obvious pattern and connection among the killings, but they're simply too _clean_. Forensics never finds anything telling about the killer; the bodies are always dumped someplace they were not killed. If they can trust the timing of the killings isn't coincidental, then someone will be murdered within the week.

To make matters worse, the media has named the culprit: The Village Killer. Since the name has circulated, bodies have been found more frequently; only one is determined to be a copycat.

There must be something, somewhere, that they missed or simply hasn't been found, yet. He could spend hours lost in his notes, but he has a sixth sense that alerts him to company, so Sehun can't appreciate the image of the detective's concentrated expression for long.

Sehun waves, kicking the door shut a bit behind him and glancing out the window as a bird takes off from the sill. “Detective, hello. Is it me you're looking for?”

Kyungsoo smiles. “Lionel Richie.” He sets the folder aside and rounds his desk, standing on his toes a bit to kiss Sehun. His hands settles on Sehun's waist, for balance, and he doesn't seem in any hurry to relinquish his hold or their kiss. The belch of air bubbles into the water cooler in the hall reminds them the door is standing open, inviting an audience.

"Is this ethical?" Sehun teases softly, tucking his fingers in Kyungsoo's back pockets. "Sir?" The title's less formality and more power kink. Detective Do Kyungsoo isn't all that much older than Sehun, but his experience and diligence on the force pushed him on the fast track from officer to detective. Sehun is just a desk jockey.

"Are you complaining, Officer Oh?" A rough palm rubs up his spine to his nape, where nimble fingers drag through his formerly styled hair.

"Not at all, sir. Just a comment."

"A little less conversation," Kyungsoo replies, teasing the underside of Sehun's jaw with his teeth, "a little more action..."

"Please." He blushes when the detective pulls back enough to give him an appraising look. "It's part of the song. ‘All this aggravation ain't satisfactioning me.’" His pronunciation isn’t as clear as Kyungsoo’s, but his conscience applauds him for not stuttering. Kyungsoo's eyes are dark, more pupil than iris, and his cheeks match the shade of pink filling his lips.

"I'm impressed you remember." 

Sharing a ride with the detective to a crime scene, the morgue, court, or even just dinner at the end of the day expands Sehun's experience with multitudes of music genres he'd never explore on his own. Hearing Kyungsoo sing in English is always a treat.

Kyungsoo walks them back from the window to his desk. The edge of the wooden desktop catches Sehun mid-thigh, and he stands on his toes a little to sit on it. The detective's hands slip down his thighs, parting them easily to stand between his knees.

Sehun slouches a little to be more level with Kyungsoo. He smiles when the man softly bumps their foreheads together. Kyungsoo, for all his overwhelming force and strength, is always kind and gentle with Sehun, even when told he doesn’t have to be.

They’re a breath apart when someone knocks on the office door. It opens fully without Kyungsoo saying anything, which means it’s his partner.

“This is my office, too, Soo; I did knock this time. Hi, Sehunnie.” Sehun waves and scoots forward so he’s leaning against the desk, rather than sitting on it. Kyungsoo doesn’t move.

“Thank you, Baekhyun. We appreciate your consideration—Where are you going? Was there a call?” Kyungsoo squints at his phone. Even on silent, a light will flash when a message comes through.

“No; I’m just late for a date.” He throws his tie and button-up shirt at the open locker behind his desk and pulls a T-shirt over his head, combing through his hair with his fingers. His weapon and badge are locked in the safe of the locker as he fumbles with his belt. Dropping his slacks around his ankles, he dances on either foot while changing into jeans. “I’ve had to reschedule twice already, because people can’t just stay out of trouble. If I cancel again, I’m pretty sure Jongin will dump me.”

“He knows the risks, dating a cop.” Kyungsoo catches the mug of pens Sehun's playing with before they fall.

“Yeah, but still. I really like him.” Baekhyun hops, pulling the pants up and closing the fly. “Also, clear the desk before doing anything, alright? Those files are our open cases, and I’d rather they not get wrinkled or sticky.” He shakes his slacks over his chair, snatching his wallet, phone, and keys. “Or just use my desk. I don’t give a fuck.

“See you later.” He waves and is gone as quickly as he’d arrived. Sehun bites his lips, feeling the heat in his cheeks. He starts when a hand slides into his own, fingers laced, and Kyungsoo leans into him, looking at the closed door with an affectionate, albeit lopsided, grin.

“I dunno about you, but the moment’s been ruined.” Puckering his lips, he plants an exaggerated kiss on Sehun's palm. A scar from a recent cooking mishap mars the flesh, and it fascinates Kyungsoo for some reason. Sehun just complains it itches, sometimes, but he doesn't mind dish duty over food prep.

Kyungsoo tugs his arm a little. “Ready to go home?” He starts to sweep up the photographs from his desk, tapping them against the wood to stack them neatly. Flipping through the pages, he quickly sets them in order. An image of the corpse sits on top; he sighs and tucks them all into a pocket of the folder, which he stands neatly in the divider of his current cases.

There’s another knock at the door; Sehun crosses the floor to open it. “I got the results from the lab, Detective.” He passes the folder around Sehun to Kyungsoo but doesn’t immediately leave, instead looking between them. “Chief’s also looking for Officer Oh. I didn’t tell her she was here, but if you want to avoid her, you should head out soon.”

Sehun sighs. His mother, the police chief, doesn’t give him special treatment on the force, but she also doesn’t treat him totally impartially, especially where his relationships are concerned. “Is she in a mood?”

“She’s definitely feeling some sort of way.” After the Village Killer's third victim was found, higher-ups have been ragging on the chief, demanding results and answers that she cannot give. In turn, she's been pushing the department and labs.

Unfortunately, there's a whole lot of nothing, like the most recent lab results.

“Thanks.” Sehun grabs his jacket, tosses Kyungsoo his, and waits in the hall while the detective locks the office door. “I still don't know how to tell her. I don't want to get you fired.”

“Why would I get fired?”

“I dunno. I'd fire someone if I found out they were banging my kid.” No matter how old the child is, they are still their parents' child. Even though his mom is a very efficient and effective police officer, she still dotes on him when she can but only with things not related to work. If she was a normal helicopter parent of station, she'd use her influence to help Sehun climb the ranks.

But no, he's a cop on his own merit. He doesn't get to go undercover or bust gangs right off the bat, but he'll get there eventually. There have been some real moments of detecting genius, when Kyungsoo or Baekhyun have talked about a case with him.

Kyungsoo takes his arm. “I honestly think she'd understand. She's a remarkable, level-headed woman and also very observant.” He wouldn't be surprised if the chief already knows about their relationship. “Do you want to come right over to my place, or should we stop for dinner?”

“I am starving. I don't think I can make it any farther than that Italian fusion place.” He tucks his arms over the detective as he gathers his keys, although he steps back to a respectable distance once they're in the hall.

They don't necessarily hide their relationship, but Kyungsoo made sure Sehun understands that there's a time and a place for open displays of affection, and in the middle of the precinct is not one of them.

After dinner, they take Kyungsoo's dogs for a walk, burn some calories at Kyungsoo's apartment, get handsy in the shower, then tumble into bed for what Kyungsoo feels are much-need cuddles. Sehun falls asleep before Kyungsoo even finishes the fourth stanza of an old Jazz standard. 

“Sweet dreams that leave all worries behind you...”

The incessant buzzing of his phone drills through the fog of sleep, and he reaches blindly until vaguely remembering his phone is still in his pants pocket, somewhere on the floor. After nearly falling out of bed, he shuffles back under the warm covers. “Do here.”

“Detective.” The chief's low, even tone commands attention, and he sits up. “There's been another murder. I've already sent Detective Byun ahead; you can meet him there. I'll text you the address.” 

She's silent, then, and Kyungsoo assumes that's it and is about to hang up when she sighs. “I know I don't have to tell you that the mayor is watching closely. It's an election year, and he thinks he can gain support by us catching this killer and showing he cares about the less fortunate.” A snort. Kyungsoo agrees with the sentiment. “Just do due diligence and catch this son of a bitch before more people end up dead.”

“We're doing all we can, ma'am.” He smacks the arm snaking around his waist. 

“By the way, you wouldn't happen to know where my son is, would you? He didn't come home last night.”

“I said 'good night' at the precinct.”

The chief sighs. “I just wish he'd tell me...”

“You're a mother before a cop, ma'am.” 

“I am. But while I don't want him to become his father, I'd rather he didn't take after me, either. Once he gets an idea... Off he goes. No word,” she sighs. Kyungsoo almost apologizes, but he can tell it's affectionate exasperation. He feels the same way, sometimes.

They say goodbye and hang up. Kyungsoo's phone immediately buzzes with the promised address. It's the same neighborhood as the others; a different building.

Behind him, Sehun lifts himself onto an elbow. “Going out?”

“Yeah.” Kyungsoo leans over to kiss his cheek. “Another body. You gonna stick around?”

Sehun drops onto his back and stretches. “It's my day off. Wish I could spend it with you. I do need to take care of Vivi, though.”

“As long as people keep killing other people,” Kyungsoo says as he crosses the room to his closet, “I won't have a full day's peace.” After dressing and dropping his wallet, keys, and phone into his pockets, he knees on the mattress to kiss Sehun again. “See you later, alligator,” he sings.

Outside, he hails a cab rather than driving his own car. Leaving anything worth anything in the open in the neighborhood he's been working in asks for trouble.

Barely a mile outside the energy and bustling economy of the city rests a sprawling neighborhood of poorly made buildings, barely-made buildings, and tents and canopies that don't even count as buildings. It's a shantytown of misfortune and destitution. Politician after politician promise to clear the area, making way for more apartments and high-rises, but the people who call it home refuse to leave.

Kyungsoo understands; they feel they have nowhere to go or simply can't afford anything else. Sometimes pride gets in the way. He still feels there's a solution, somewhere, that could help everyone, but he's a cop, not an urban developer.

The cab driver, for their part, isn't too nervous driving to the slums, but she says outright she won't wait and passes a card to Kyungsoo with her car and phone number on it.

Squad cars block the street. Yellow tape forms a barrier around the sad building, its side painted with gang graffiti and attempts to bring some color to the area. 

The driver barely waits for the door to close before making impressive, multiple Y-turns and going back the way they'd come.

Uniforms keep curious bystanders back. They ignore the bitter remarks from the residents. It takes a murder for police to show up and express any sort of concern for their safety.

Kyungsoo steps over a drunk man passed out on a pile of cardboard and ducks under the tape. An officer says Detective Byun is already inside and the body hasn't been moved, because they're waiting on the medical examiner.

Forgoing any pleasantries, Baekhyun glances up from his position beside the corpse and shakes his head. “You know it before you even see it. It's the same thing—multiple stab wounds, massive blood loss. It's torture or overkill.” They both suspect the deaths are related to gang activity, the only family and safety many people in the slums have.

“What's weird is this is an older body, Soo. He's been dead for a while, and he wasn't killed here.” Pointing up, Baekhyun adds, “No spatter on the ceiling or walls. No puddle underneath. Had to have been moved here, cleaned impossibly well, or—”

“No, hyung.”

“--murder bubble.” An enclosed space for a killing to take place that can be collapsed and removed after the deed is done. To be fair, they have seen a number of strange things in their investigations; nothing like Baekhyun's 'murder bubble.'

Kyungsoo rubs his neck. “We have to find another site for the killing itself. Nobody around here is going to cooperate.” And sending uniforms throughout is a big operation. It's the right thing to do, but he can just hear the mayor complaining about spreading the force thin in that neighborhood when there are citizens to serve within the city itself. Citizens with money who are more likely to vote in the elections.

“Do we know who called it in?”

Baekhyun nods and gets to his feet. “Some urban explorer-slash-activist.” A kid with a camera and a self-guided mission to expose others' misfortunes in the hopes of shocking the public to act. “Says they didn't touch anything, but they nearly threw hands when their camera was taken for evidence.”

He notices the lines between his partner's eyebrows, a trait revealing his frustration, and claps Kyungsoo on the shoulder.

“Maybe we'll get lucky this time. Depending on which one this is, we could get a break. Early killings aren't as finessed as when they know what they're doing.” Ever the optimist. It's a rare trait in a homicide detective.

After looking over the rooms and finding nothing immediately relevant, the detectives leave it to the forensics team and ask officers to take statements from whoever is willing to talk, calling another cab to take them to the precinct.

It takes a couple of days, but they do get a break.

While Baekhyun is teaching a defense class, a forensics technician brings news of not only fingerprints but matches in the database. She doesn't immediately let go of the folder as she passes it to Kyungsoo, stressing that she ran the prints twice, and they are accurate.

“What is it?” Leaning back in his chair, Kyungsoo frowns at the woman nervously biting her lip. “Someone you know?”

“You, too, sir...” She hastily bows and leaves.

It can’t be right; his heart doesn’t want to believe it, but his head trusts in science. Kyungsoo cross-checks the estimated times of death with the work schedule, plus the days he knows were off, and it fits.

He can't believe it. It would all be too much of a coincidence, if wrong, and he has only experienced true coincidences a mere handful of times.

Within the hour, he's certain of the means and opportunity but not the motive aside from mysterious gang involvement. Motive is where Baekhyun shines as a detective, though, and Kyungsoo takes the time until his return to find some sense of calm.

Finally, boisterous laughter announces Baekhyun's arrival. He bursts into the office, pink-cheeked and running on adrenaline after an hour of throwing rookies across the room and tormenting his volunteers with blocks and jabs.

“Hyung. CSI found a match for the fingerprints they found.”

Baekhyun throws himself into his chair and spins once. “Finally!” He snatches the folder with the results, not noticing the pensive silence. “What scum do we get to scour off the face of the city?” 

He stills, exuberance slowly dimming, and flips between pages, as though searching for more.

“Soo...” Shaking his head in disbelief, he looks at his partner. “Do you know where he is today?”

“He didn’t say,” Kyungsoo mutters, unlocking his phone, “but I can probably find out without needing a warrant or subpoena.”

Sehun has a habit of posting on social media throughout the day, including a location that shares an address when opened. Within a few minutes, Kyungsoo has a lead.

“Let's go.”

They drive in silence, going as fast as they can without lights. Construction forces them to detour, but both detectives try not to think what could be happening in the time it takes them to find their way.

Baekhyun pulls into a parking garage, and they trek into the open air. Traffic isn't heavy near the outskirts of the city. There are more bicyclists and skateboarders. A fluffy Pomeranian shakes its tail at them before being pulled along by its owner.

Checking his phone, Kyungsoo scowls at the bubble tea shop across the street. A happy cartoon character points out the new flavors as a banner from a massage shop flaps in its face. Beside that is a noodle restaurant tempting pedestrians with spicy smells. A massage parlor with a neon arrow pointing down some stairs leading to more neon outlines of hands and bodies stands on its other side.

“We’re not far from the village,” he remarks, pocketing his phone. “It’s about a fifteen minute drive.”

Returning to the parking garage to retrieve their car, Baekhyun’s unusually quiet. He’s no longer sulking, like before; his face is set and determined.

For once, Kyungsoo doesn’t appreciate the quiet. His partner’s chatter would be a welcome distraction and comfort. Baekhyun feels similarly and turns on the radio, cutting the static between them with croons of heartbreak.

A soundtrack for life.

As he merges with traffic and follows the flow south, the affluent neighborhoods of high-rises and restaurant and boutiques shrinks and thins. Crossing an expressway, the skyline clears, allowing the sun to shine fully on the shacks of the shanty town.

It's as ugly as ever; Kyungsoo can't get used to the appearance and the smells that immediately assault them when they step onto the littered sidewalk.

“Now what?”

“I have an app that can track his phone.” He's one of the contacts, in case Sehun's phone was stolen or misplaced.

“It won't alert the phone, will it?”

“Not if I don't tell it, too...” He pinches the map and tries to figure out where the phone is versus his location, but the village isn't mapped out as neatly as the city. Baekhyun points out the highway and determines they need to head east.

After a home made of scrap metal, there's a shell of a warehouse. Kyungsoo dials Sehun's number.

A familiar ringtone sings faintly inside the warehouse. Baekhyun motions that he's going to walk around the building, and Kyungsoo nods. He'll wait.

“Hello?”

“Hey, Sehun. I'm about to leave. Where are you?”

“Out.”

“Want me to pick you up?”

“No... I think I'll just head home. Spend some quality father-son time with Vivi.”

“Alright. See you later.”

“Bye, hyung.”

Tucking his phone back in his pocket, Kyungsoo shudders. At the same time, he feels like crying.

Baekhyun hisses as he comes around the corner behind Kyungsoo. “Windows are boarded up, and the only other door would hit another house; it's not usable. I called in backup. Ten minutes.”

They wait eight before quietly opening the door and entering the warehouse with their weapons drawn. It's a spacious room, divided from the rest of the building by a partial wall topped with hazy Plexiglas. Old crates, newspaper, soiled rags, and empty bottles sit beneath a blanket of dust. The only light is from the open door and the next room.

In the middle of the next room is something like a studio. Plastic hangs from the ceiling and covers the floor. A lamp casts glaring white light, leaving nothing to the imagination. Leaning against its base is Sehun's phone, smeared with bloody fingerprints.

“ _Freeze!_ ”

A beat later, Baekhyun nudges Kyungsoo aside and advances steadily. “Drop the knife, Sehun. Hands behind your head.”

He obeys. The knife drops with a clatter, blood jumping from the blade and spattering in needles across the floor nearby. There’s no hesitation in lacing his fingers over his hair. 

“I thought you were at the precinct.”

“Surprise.”

Sehun stares at them evenly, although Kyungsoo realizes he’s actually looking passed them when he steps beside Baekhyun after checking for a pulse on the victim. They're pockmarked with stab wounds and obviously dead.

Torture or overkill.

Kyungsoo pops a button on his belt and retrieves a pair of white zip ties. “You’re under arrest. You have the right to remain silent...”

As his rights are rattled off, Sehun’s mute. He doesn’t fight the ties, holding out his arms meekly and only pulling them once, as though testing the strength of the plastic. If the hand on his shoulder is gentler than on other suspects, neither man acknowledge it out loud, and Sehun steps into the backseat of the car without being guided.

Kyungsoo allows himself a moment for a shaky breath after shutting the door, shaking his head and motioning to a uniformed officer to drive the squad car, and its captive occupant, to the station for booking.

“Who taught who the cold hard facts of life...” he mutters.

Baekhyun, having stayed a few steps away, walks up beside his partner and touches his back. “I’m sorry, Soo.”

“So am I.”


End file.
